Piston expander



Aug. 27, 1940. D. M, SWTH Er AL 2,212,817

PISTON EXPANDER Filed Jan. 6, 1940 1'1 Eyg7kAM-7/( PL N I Arro MEX Patented Au 27, 1940 PISTON EXPANDED.

Dallas M. 'Smith, Kirkwood, and George C. Mayiield, Richmond Heights, Mo., assignors to McQuay-Norris Manufacturing Company, St.

Louis, Mo., a corporation of Delaware Application January 6, 1940,, Serial No. 312,752

3 Claims.

Cur invention relates to piston expanders, and more particularly to expanders for pistons of the type having an axially extending slot in the skirt thereof. Our invention is directed towards providing simple and eflicient means for separating parts anchored in the marginal portions or the skirt at each side of the slot, so that these portions in turn, will be moved away from one another to increase the circumference of the skirt,

1. and thereby to compensate for wear in use.

The object of our invention is to provide a simple, cheap and effective expander, which may be installed quickly and easily, and yet will be highly eflicacious in operation.

II In the accompanying drawing wherein simflar characters are used to designate similar parts, we have shown an embodiment of our invention in its simplest form, but have shown two methods of mounting the expander on a piston. In 20 this drawing,

Fig. 1 is a view of our expander assembled on a piston;

Fig. 2 is a section along the lines 2--! in Fig. 1; Fig. 3 is a view similar to Fig. 2, but with the 28 parts in a different position;

Fig. 4 is a section along the lines 4-4 in Fig. 2; Fig. 5 shows a modified form of mounting our expander ,on a piston; and

Fig. 6 shows the parts of the expander proper to as used in Figs. 1 to 4, inclusive.

Referring to the Figures 1 to 4, inclusive,and 6, the piston A shown as being of the general type to which our new and improved expander may be applied, has a head B, including the usual ring 85 groove C, and a skirt D, depending from the head and separated therefrom by the circumierentially extending slots E. The piston A has an axially extending slot F therein, preferably at a point removed approximately ninety degrees from the 40 pin bosses G of the piston. The pin bossees G in turn, are adapted to receive a wrist pin H, upon which is mounted the connecting rod J.

This embodiment of our invention includes an expander, as shown in detail in Fig. 6, compris- 45 ing a pair of parts K, each adapted to be anchored in a marginal portion 01 the skirt D, at each side of the slot F. The anchoring of the parts K to these marginal portions, may be ac-f complished by any suitable expedient.- As

60 shown in-Flgs. 1 to 4, inclusive, each part K is" provided with a short flange L, adapted to enter the slot F, and engage an edge of the skirt D.

The opposite end of the part K is hooked as at M, to provide a portion to be engaged by the ex- 65 panding means, as described below. The parts K (01. cos-.12

the skirt will be eflectively increased. In this embodiment, the means for separating the parts K is a member P, including a modified overthrow cam arrangement, which has knuckles Q having their outer surfaces non-parallel, and.

each formed withan aperture to receive aliool:

M of a part K.

The installation and operation of this embodiment'of our invention is as follows: The pair of parts Kare mounted in alignment onthepiston skirt with the flanges L extending into the slot F, and engaging the adjacent edges of the skirtat opposed points. The knuckles Q of the overthrow cam are positioned to surround the hooks M. Theparts K and the overthrowcamare of such size and arrangement that when the memher P is in the position shown by the dotted lines in Fig. 2, no separating force will be exerted against the parts K. 5 However, when the member P is moved in the position shownain Figs. 1,

3 and 4, the non-parallel sides of the knuckles Q will engage the bases of the hooks M, and will 7 force the parts K away from one another. In turn, because the parts K are. anchored to the marginal portions of the skirt, when theparts are moved away from the slot these marginal portions willbe separated, and the eflective diameter of the. skirt will be increased.

If the member P is formed s shown with a pair or lever arms connected by a; loop, and hit is formed of springlwire or other suitable and .similar material, the action ofthe overthrow cam will be augmented by a spring tension generated in the connected lever arms.

In Fig. 5', as stated above, we have shown a slightly modified manner of mounting our ex- 46 pander d a pistson. Here a pair of holes'R are drilled 0 otherwise formed in the skirt D, "with one of said holes being ateach side of the slot F. Flanges L of parts K are engaged in the holes,

and the member P coooperates with the hooks M to move the parts to expand the piston skirt as in the form first described. Wingsjlif may be provided to engage the skirt.

From the above description itwill' be obvious that an expander embodying -.our i'nvention-will 5 be simple and highly effective. However, we do not intend to limit ourselves to the exact embodiment shown, because the various parts may be varied in size, shape and arrangement without deviating from the spirit of our invention as included in the appended claims.

What we claim as new and desire to secure by Letters Patent, is:

1. An expander for a piston skirt having an axially extending slot therein, said expander comprising a pair of parts anchored in the marginal portions of said skirt adjacent said slot, and a member including an overthrow cam engaging said parts and movable into a position to move said parts away from one another, whereby the marginal portions of said skirt will be separated to increase the circumference thereof,

2. An expander for a piston skirt having an axially extending slot therein, said expander comprising a pair of parts anchored in the marginal portions of said skirt at each side of said slot, each of said parts having a hook formed thereon, and a member having a pair of knuckles each engaging one of said hooks, and said knuckles being adapted and arranged to be movable into a position to move said parts away from one another, whereby the marginal portions of said skirt will be separated, and an expansive action will be exerted thereon.

3. An expander for a piston skirt having an axially extending slot therein, said expander comprising a pair of parts anchored in alignment in the marginal portions of said skirt at each side of said slot, each of said parts having a hook formed thereon, and a resilient member having a pair of knuckles with non-parallel side faces. and each of said knuckles engaging one of said hooks, and said member also including a pair of resilient lever arms connected at their outer ends and carrying said knuckles at their inner ends, and said member being adapted and arranged to be movable into a position to cause said knuckles to move said parts away from one another, whereby the marginal portions of said skirt will be separated and an expansive action will be exerted thereon.

DALLAS M. SMITH. GEO. C. 

